This is the answer about the lifecycle of propretary, device and manufactor dependent software So I am glad to see they go with standards now: HTML5 and CSS.

Cheers

Know all those Mobi files floating around? They still work in every one of the 30 million Kindles out there and untold millions of Kindle Reader apps for PCs and Android. Plus whatever devices run FBreader and coolreader.

How many HTML5/CSS ebook readers are actually in use out there?
(Aside from the proprietary-as-heck Kindle FIRE?)

Let's not get carried away with "standards" fever, okay?
Hyped "Standards" come and go, but it is the useful stuff that survives.